This disclosure relates to a desalination apparatus and a process that can be used to remove sulfur dioxide and other environmentally hazardous contaminants from a gaseous waste stream while at the same time providing a source of purified water and providing a means to dispose of contaminated water.
Metal smelting operations generally produce a large amount of byproduct gases during the conversion of the metal ore into a metal. For example, in the smelting of aluminum from alumina, byproduct gases that comprise carbon dioxide (CO2) and sulfur dioxide are produced at the rate of about 500,000 to about 1,800,000 cubic feet per minute depending upon the size of the plant. These byproduct gases are generally released into the atmosphere at temperatures of about 80 to about 100° C.
Sulfur dioxide is an environmentally hazardous contaminant that facilitates the production of acid rain. It is therefore desirable to remove sulfur dioxide from the byproduct gases that are released into the atmosphere.
In addition, the discharge of water that has been contaminated through contact with various parts of the process in smelting plants may pose an environmental hazard. It is therefore desirable to concentrate contaminants in such waters to as high a level as possible, thus limiting the amount of water that needs to be disposed of or processed further.